Impacts of Decoy Effects on the Decision Making Ability

Decision support systems found on many e-sales platforms, such as recommender- or configuration systems follow the aim of calculating and suggesting the best solution for a decision task (e.g. optimal product or service). When the optimality of the solution is defined in a multi-dimensional way(i.e. depending on multiple factors), calculating a single optimal solution item is typically not sufficient or representative. For example, the optimal product can be subject to price, availability, quality features, and many others. For such decision tasks it is normally more appropriate to come up with a set of possible solutions which the decision maker has to choose from. In decision situations with many solutions offering different advantages and disadvantages severe decision dilemmas may occur which can paralyze or delay decision making. Also the objectivity can be blurred as different decision biases can occur. This paper introduces the notion of decoy effects as one family of decision biases which not only impact on the decision outcome but also on the self confidence in decision making. Based on the results of a corresponding user experiment, an in-depth-analysis of the influences of decoy effects on the decision taking ability is given. To this end, the interactions of decoy effects, solution set size, decoy minimization (i.e. the concept of adding mutually neutralizing decoys), time consumption for decision making, and the self confidence in a decision situation are investigated. As significant impacts on the decision-taking ability can be shown, this paper forms the grounding forth implementation of intelligent mechanisms for customized decision support in terms of decision time, decision confidence, and objectivity.